It depends on the complexity of your band music (and the flexibility of your publisher). Your publisher may simply want the Finale file format to avoid entry and plan to do their own formatting of your work, in which case a lower tier program like Printmusic might work. Your best bet is to ask your publisher before you order.

Assuming you're getting paid to do this, $600 is a business expense, and one that would hopefully pay off eventually. Are you a teacher? Then you would qualify for the educator discount, too. But if the publisher wants Finale format, that's what you should give them.

I do freelance engraving work for a large educational publisher.

If your publisher sends you custom fonts and templates, you'll probably need the full Finale in order to work comfortably within their workflow. If they're willing to take whatever you send them, as long as the notation is fully complete, you could get away with Print Music. They could open those files in Finale in order to edit them.

Unfortunately, MuseScore is worth every penny you paid. I have it and in many ways, it's just not ready for prime time—lord knows I tried to make it live up to expectations. Even its MusicXML export isn't that great, certainly not up to Finale. 

If you go with a lesser version and you need a feature found only in the full version, then the lesser version was a waste of your money (except as credit towards the upgrade). In addition, when you buy the program, you are paying for tech support—and you are on Windows 10 which makes you braver than I  

Do you have nothing eligible for the $149 competitive upgrade? (Sibelius, Encore, Overture, Score or Notion). If you own any of these, you can take advantage of the cross-grade  

https://store.makemusic.com/Store/Beyond.aspx?_ga=1.112757380.1885160635.1383283867